The succession of GH6 cellulase-producing microbial communities and temporal profile of GH6 gene abundance during vermicomposting of maize stover and cow dung

Abstract

Vermicomposting eco-friendly converts lignocellulosic wastes into bio-organic fertilizer. Cellulose is the most abundant carbohydrate in lignocellulose. Glycoside hydrolase family 6 (GH6) plays a key role in the early step of cellulose degradation, which is essential for stabilizing lignocellulose. This study intends to quantify the abundance of GH6 gene and to clarify the succession of GH6 cellulase-producing microbial communities during vermicomposting. 100% of maize stover (A) and maize stover and cow dung at 60:40 ratio (B) were used. The results showed that different native genera were observed in the starting materials. Cellulomonas and Cellulosimicrobium were dominant genera harboring GH6 gene. The peak relative abundance of Cellulomonas was 76% and 30% in B and A during vermicomposting phase, and the corresponding values of Cellulosimicrobium was 36% and 37%. Earthworms increased the abundance of GH6 gene, which reached 1.51E + 09 from 3.46E + 08 copies/g in B. The results partially interpreted promoting effect of earthworms.